It is well known in the art that HFC-32 may be used as a replacement for environmentally disadvantageous chlorofluorocarbon refrigerants, blowing agents, and aerosol propellants. A variety of methods for the vapor phase production of HFC-32 are known.
For example, U.S. Pat. No. 2,745,886 discloses a vapor phase process for fluorinating a variety of halohydrocarbons including methylene chloride, HCC-30, which process utilizes a hydrated chromium fluoride catalyst activated with oxygen. Similarly, U.S. Pat. No. 2,744,148 discloses a halohydrocarbon fluorination process in which an HF-activated alumina catalyst is used.
U.S. Pat. No. 3,862,995 discloses the vapor phase production of HFC-32 by reacting vinyl chloride and HF in the presence of a vanadium derivative catalyst supported on carbon. U.S. Pat. No. 4,147,733 discloses a vapor phase reaction for the production of HFC-32 by HCC-30 with HF in the presence of a metal fluoride catalyst.
In practice, these processes for HFC-32 production suffer from a variety of problems including low product yield and selectivity as well as operational difficulties such as feed decomposition. The process of this invention provides for the production of HFC-32 by a process that overcomes some of the disadvantages of the known processes